To his neighbours in the sedate and modest Old Mill estate in Ratoath, Co Meath Noel Duggan was known as someone who made a €4m settlement with the Criminal Assets Bureau 13 years ago but, otherwise, was now an ordinary citizen businessman.

To his neighbours in the sedate and modest Old Mill estate in Ratoath, Co Meath Noel Duggan was known as someone who made a €4m settlement with the Criminal Assets Bureau 13 years ago but, otherwise, was now an ordinary citizen businessman.

Duggan avoided the drugs trade despite its high profit margin because of its accompanying high risks, gardai said last week. Two hundred men involved in the drugs trade have been assassinated in Dublin in the past decade and, at no stage, was Duggan ever known to be involved in any of the organised violence.

His business was in the high volume, low-profit trade in illicit tobacco. In the Republic this trade probably accounts for one-in-every-five cigarettes sold and industry sources estimate the illicit trade probably generates profits of around €500m a year.

Duggan had been involved in cigarette smuggling since the 1980s when he ran a small warehouse, fronting as a fruit and veg outlet in Smithfield selling a variety of cheap imported goods. He was well known to gardai, having been involved in petty crime since his teen years but by the time he set himself up as an importer and trader he had gained a level of respectability with gardai among the customers at his Smithfield premises.

His business focus was confined to the north inner city where he grew up and he bought property cheaply with profits from the cigarette smuggling. In 2003 he handed the deeds of a retail and apartment complex he built in Smithfield by way of settlement of a €4m bill for unpaid tax. That aside, and despite his newspaper nickname, 'Mr Kingsize', he was never known to have been involved in any of the previous bloody feuds in Dublin.

Garda sources said yesterday Duggan (58) was murdered, almost certainly, because he was a simply a friend of Gerry Hutch and part of a widening list of 'easy' targets that are being drawn into what is potentially the biggest ever gang feud in Ireland.

Hundreds of people depend directly on the cigarette business that Duggan built up over nearly four decades. His product, packs selling at €4.50 and cartons of 20 packs at €40, were on sale last week in central Dublin but the future of this trade is now uncertain.

One obvious concern for gardai is that Duggan had known associations with the Provisional IRA who seized control of the tobacco importation business in 2001 after the murder of Kieran Smyth, a south Armagh man with no paramilitary connections who had become a major figure in cigarettes and, increasingly before his murder, the importation of drugs and guns. With Smyth's murder in February 2001, the IRA took over the logistics of cigarette importation using the same routes they had built up to supply weapons during the Troubles.

Cigarettes and fuel are the mainstays of the IRA's criminal operations. A document drawn up by Spanish police last year during the seizure of property and bank accounts controlled by IRA cigarette smugglers stated that aside from the obvious level of self-enrichment, 25pc of profits was going to the 'organisation' - the overarching 'Republican Movement' that comprises the IRA and its political wing, Sinn Fein. The court document cited the British Intelligence service, MI5, as its source.

Gardai believe Duggan struck a deal with the Provos, maintaining his distribution network supplying a substantial part of the illicit tobacco trade in the city.

Duggan's Illicit cigarette traders maintain their core, daily business with a protected float of cash but when they make extra profits they will divert this into buying drugs to sell at a higher profit.

Gardai believe Duggan (58) was murdered as part of a campaign by the Kinahan cartel to destroy the northside gangs entirely.

Although there has been more or less constant feuding in Dublin over the past 20 years, gardai say they have never encountered anything like the current state of fear and paranoia in the city.

The potential victim list in this feud is nothing like the run-of-the mill young gangster but includes people who live a non-ostentatious lives in suburban estates with their money salted away in foreign investments.

Another major target for the northside gangs is a well-known criminal figure based in southwest county Dublin. He and some associates control the heroin and cocaine trade in and around a large part of west Dublin.

Other major targets on the southside of the Liffey are members of the extended family that controls almost the entire drugs trade in the south inner city area. This family has many members involved in legitimate and semi-legitimate 'front' businesses which they necessarily have to attend to on a daily basis. This group, gardai say, are feeling particularly vulnerable at present. They have almost never featured publicly in any of the news coverage of Dublin's drugs trade and gang feuding.

Garda sources say that they now see no end or settlement in sight to this feud and very much fear what one termed a 'bloodbath' type of attack. This fear will have been reinforced by the fact that Noel Duggan's trading partners include the Provisional IRA.

The last time they were involved in a feud in Dublin, during a vicious but short-lived feud in the north inner city, they brought grenades from Belfast which are presumed to still be in Dublin.